Yup, sure did.
While searching for solutions, I discovered that Ren'Py games also frequently save files in c:\users\username\appdata\roaming\RenPy\ as well, so I checked that and deleted them to get rid of old save files so they'll stop eating up drive space. I also hoped that would eliminate the exception error screens that keep coming up after I tried a mod that I hoped would restore the missing images. It did not; no matter how often I wipe the extracted game and start over from scratch, it continue to retain the modification and, of course, crashes the game unless I put the mod back in. That file location info is new to me; had to hunt around on my hard drive searching my profile to discover THAT bit of information.
Update while writing this: It seems that I managed to clear the multiple exception errors by turning DM off, then quitting the game, then starting it back up. Now it appears to be running free of THAT set of errors and it lets me turn DM back on without errors, but the images of Yuki are still not loading and appear to have sex scenes with other characters in their place. It's not preventing me from playing, but it is jarring not to have some continuity between the text of the story and the images on screen. If anyone has an insight into this, I'd appreciate even just knowing it's deliberate and intentional.